The invention relates to an airbag device and to a method of operating an airbag device.
Published, Non-Prosecuted German Patent Application Nos. DE 197 26 878.1 and DE 197 33 896.8, European Patent Application No. EP 0 867 346 A1, and International Publication No. WO 99/61288 disclose conventional airbag devices and methods of triggering or operating such airbag devices.
It is an object of the invention to provide an improved airbag device and a method of operating or triggering an airbag device.
It is in particular an object of the invention to provide a space-saving construction for an airbag device and an operating method for such a construction. The present invention can be employed as a supplement to the subject matter of the above-mentioned patent applications, and, in an advantageous manner, can further reduce the so-called xe2x80x9caggressivenessxe2x80x9d of the airbag in that a mechanism pulls the airbag cover into the dashboard.
The present invention relates in particular to improvements of airbag systems and exemplary embodiments dealt with in the above-mentioned patent applications, especially as regards the construction of the airbag device and the triggering/operating control system and, specifically, to a device and a method for controlling an airbag flap or airbag cover. The disclosure of the above-mentioned patent applications especially as regards the construction of the airbag device and the triggering/operating control system and, specifically, the embodiments for controlling an airbag flap are incorporated by reference into the present application.
With the foregoing and other objects in view there is provided, in accordance with the invention, an airbag device, including:
an airbag module defining an airbag exit path, the airbag module including a piston, the piston being configured to be subjected to a pyrotechnical action such that the piston performs a linear movement when being acted upon;
pulling devices;
at least one airbag cover connected to the piston via the pulling devices, the at least one airbag cover being movable from a closed position into an open position when the piston is acted upon, the at least one airbag cover, when in the closed position blocking the airbag exit path, and the at least one airbag cover, when in the open position, clearing the airbag exit path; and
a helical positive guide for guiding the piston such that the piston, when being acted upon and performing the linear movement, also performs a rotational movement for winding up the pulling devices.
In other words, the invention provides an airbag device with an airbag module and at least one airbag cover, which is connected to a piston through the use of pulling devices, which piston can be subjected to pyrotechnical action in order to produce a linear movement, and, when the piston is acted upon, the airbag cover moves out of a closed position, in which it blocks an exit path of an airbag out of the airbag module, into an open position, in which it clears the exit path of the airbag out of the airbag module, a helical positive guide being provided for the piston, and the pulling devices being configured in the form of cables, so that, due to the action upon it, the piston performs a rotational movement during its linear movement, winding up the pulling devices as it does so.
This is a particularly advantageous way of using a linear actuation of the piston, which can be achieved easily, reliably and economically, and combining it with a space-saving way of winding up the pulling devices.
Preferably, the positive guide is formed by at least one guideway along the path of movement of the piston, which piston has at least one extension, which rests against the guideway or engages in the guideway. In this configuration, the at least one extension can be formed by a bolt or a screw. It is also possible for two extensions, spaced apart in the direction of its linear motion, to be provided on the piston, and for a guideway to be assigned to each of these two extensions. In this configuration, it is particularly preferred if the pulling devices engage on the piston through the use of the extensions of the piston.
It is furthermore preferred if the pulling devices include at least one wire, cable or strap, through the use of which the airbag cover is connected to the piston. In this configuration, provision is preferably made for the cable or the wire to be composed of metal, or for the strap to be composed of a textile material or plastic or a mixture thereof.
According to further preferred embodiments of the invention, the piston is placed in a cup-like manner over a gas generator of the airbag module and/or the piston is guided in a housing of the airbag module, in particular, if appropriate, the piston is guided by a housing of the gas generator.
The guideway preferably includes a control edge or a slotted guideway.
With the objects of the invention in view there is also provided, a method of operating an airbag device, the method includes the steps of:
providing an airbag module having a piston;
providing at least one airbag cover connected to the piston via pulling devices; and
subjecting the piston to a pyrotechnical action such that the piston performs a helical movement for winding up the pulling devices such that the pulling devices pull on the at least one airbag cover and move the at least one airbag cover from a closed position blocking an airbag exit path into an open position clearing the airbag exit path.
In other words, the object of the invention is furthermore achieved by an operating method for an airbag device, wherein at least one airbag cover is moved out of a closed position, in which it blocks an exit path of an airbag out of the airbag module, into an open position, in which it clears the exit path of the airbag out of the airbag module, through the use of pulling devices, by a piston, which is subjected to pyrotechnical action in order to produce a linear movement, and, due to the action upon it, the piston performs a helical or screw-like movement, winding up the pulling devices as it does so, so that the pulling devices pull the airbag cover and move it from the closed position to the open position.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in an airbag device and a method of operating an airbag device, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.